This device relates generally to electrically operated devices and more particularly to an improved solenoid device which may assume the form of a solenoid actuator or solenoid valve. Such devices find application in a number of areas for controlling fluid flow, including industrial applications, automotive, irrigation, etc.
A solenoid device comprises an electrical coil which when energized, produces an electromagnetic field that is utilized to perform some function. In the case of a solenoid actuator, the electromagnetic field is utilized to move a magnetic armature. A solenoid valve is essentially a solenoid actuator having a portion thereof adapted for controlling fluid flow.
U.S. Pat. No. 5,311,162 discloses a valve actuator solenoid with an encapsulated coil removably mounted on a central core and an armature controlling fluid flow through the valve. The patent discloses that it is desirable that the coil be removable in the event its fluid isolation structures are penetrated allowing fluid to reach the coil and thereby inhibit coil function.
U.S. Pat. No. 5,358,215 discloses another solenoid actuated valve for controlling air flow in an automatic suspension system for a vehicle. This patent discloses winding the coil on a housing over the core and plunger area. The core is fixedly attached inside the internal passageway to prevent its movement during operation. The patent discloses a valve having an internal passage that extends the full length of the housing with apertures on both ends. The first aperture is for coupling to a fluid supply source, while the second aperture permits the flow of air to the suspension in the automobile.
One disadvantage of the above described solenoid valve is that the internal valve seat is formed in the molding process of the valve housing. This molding process requires high tolerances to produce a valve seat that will precisely mate with the corresponding surface on the plunger to form an air-tight seal. Further, once molded, the valve seat cannot be replaced when worn or modified for alternative applications. Moreover, the electrical connection for energizing a coil is located adjacent the fluid connection point such that the device is not suitable for many applications since any fluid leaking at the fluid connection point would exit the device adjacent the electrical leads and potentially damage the electrical components of the solenoid actuated valve.
Accordingly, there remains a need for a simple, substantially fluid resistant solenoid actuated valve that is adaptable to a number of different systems.